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2C-T-21 Stats & Data

Psychedelic Research-chemical

Aurora

NPS DataHub

MW259.34

FormulaC12H18FNO2S

CAS207740-33-8

IUPAC2-[2,5-Dimethoxy-4-(2-fluoroethylthio)phenyl]ethanamine

SMILESFCCSc1cc(OC)c(CCN)cc1OC

InChIKeyZBUUUKBTOCTOPW-UHFFFAOYSA-N

Phenethylamines; 2020/1. Von 2-Phenethylamin abgeleitete Verbindungen; 2021/1. Von 2-Phenethylamin abgeleitete Verbindungen; 2022/1. Von 2-Phenethylamin abgeleitete Verbindungen

Chemical Class Phenethylamine

Psychoactive Class Psychedelic

Half-Life Unknown in humans; effect duration typically 6–12 h.

Receptor Profile

Receptor Actions

Agonists

5-HT2A receptor agonist (partial)

Inhibitors

Possible MAO-A inhibitor (reversible, weak)

History & Culture

1991–present

2C-T-21 was first synthesized by Alexander Shulgin, representing the final compound in the 2C-T series to be completed. Shulgin and colleagues first described the substance in scientific literature in 1991, with detailed documentation appearing in his book PIHKAL (Phenethylamines I Have Known and Loved).

Psychedelic researcher Myron Stolaroff discussed 2C-T-21 in his book Thanatos To Eros, 35 Years of Psychedelic Exploration, characterizing it as "not psychedelic, but a wonderful energizer" and noting an unusual absence of the appetite suppression typically associated with other members of its class. However, Stolaroff also expressed concerns regarding the compound's potential toxicity.

2002–2005

On March 9, 2004, a 22-year-old quadriplegic man named James Edwards Downs in St. Francisville, Louisiana consumed an unknown quantity of 2C-T-21 by placing his tongue into a vial of powder he had purchased online. He developed a temperature of 108°F (42°C), experienced a tonic-clonic seizure, and entered a coma. Four days later, on March 13, Downs died at Lane Memorial Hospital in Zachary, Louisiana. This fatality became part of Operation Web Tryp, a two-year DEA investigation launched in 2002 targeting the online distribution of research chemicals. On July 22, 2004, the operators of American Chemical Supply were arrested on federal charges relating to distribution of controlled substance analogues in connection with Downs' death. The defendant pleaded guilty in March 2005.

Effect Profile

Curated + 28 Reports

Psychedelic 8.8

Strong visuals, headspace, auditory effects, and body load

Visual Intensity×3

10103.2

Headspace Depth×3

10103.8

Auditory Effects×1

10102.5

Body Load / Somatic Effects×1

10103.5

Catalog Erowid BlueLight

Based on reports from:

PiHKAL PiHKAL #49: 2C-T-21 Erowid Experience Reports PsychonautWiki 2C-T-21

Tolerance & Pharmacokinetics

drugs.wiki

Half-Life

Unknown in humans; effect duration typically 6–12 h.

Addiction Potential

Very low. Like other classic psychedelics it is not habit-forming and shows rapid tolerance that discourages frequent re-dosing.

Experience Report Analysis

Erowid BlueLight

20 Reports

2003–2017 Date Range

2 With Age Data

20 Effects Detected

Demographics

Gender Distribution

Age Distribution

Reports Over Time

Effect Analysis

Erowid + Bluelight

Effects aggregated from 28 experience reports (20 Erowid + 8 Bluelight)

28 Reports

64 Effects Detected

36 Positive

16 Adverse

12 Neutral

Effect Sentiment Distribution

Confidence Distribution

Positive Effects 36

Stimulation 57.1% 81%

Tactile Enhancement 53.6% 88%

Introspection 46.4% 82%

Euphoria 46.4% 84%

Music Enhancement 42.9% 93%

Empathy 39.3% 78%

Mood Lift 37.5% 87%

Focus Enhancement 35.0% 70%

Color Enhancement 32.1% 88%

Analysis Enhancement 25.0% 81%

Sociability Enhancement 25.0% 80%

Patterning 25.0% 82%

Joy 25.0% 85%

Thought Acceleration 25.0% 80%

Tactile Intimacy Enhancement 25.0% 86%

Body High 21.4% 88%

Tingling 12.5% 85%

Love 12.5% 90%

Warmth 12.5% 88%

Mystical Quality 12.5% 75%

Adverse Effects 16

Nausea 42.9% 85%

Thought Disorganization 37.5% 76%

Anxiety 25.0% 88%

Body Load 25.0% 69%

Jaw Clenching 21.4% 90%

Muscle Tension 21.4% 80%

Pupil Dilation 20.0% 70%

Confusion 15.0% 70%

Paranoia 12.5% 85%

Restlessness 12.5% 82%

Loneliness 12.5% 85%

Dysphoria 12.5% 78%

Insomnia 12.5% 80%

Headache 12.5% 85%

Sweating 12.5% 85%

Field Narrowing 12.5% 75%

Dosage Distribution

Dose distribution from experience reports

Median: 10.0 mg IQR: 8.0–12.5 mg n=12

Real-World Dose Distribution

62K Doses

From 28 individual dose entries

Oral (n=19)

Median: 10.0mg 25th: 8.0mg 75th: 11.5mg 90th: 13.0mg

mg/kg median: 0.142 mg/kg 75th: 0.164

Form / Preparation

Most common forms and preparations reported

Body-Weight Dosing

Dose relative to body weight from reports with weight data

Median: 0.134 mg/kg IQR: 0.095–0.158 mg/kg n=12

Redose Patterns

Redosing behavior across 19 reports

21.1% Redosed

1.2 Avg Doses

1m Median Interval

Read full reports on Erowid →

Legal Status

Country	Status	Notes
Austria	Illegal (NPSG)	Possession, production, and sale are prohibited under the Neue-Psychoaktive-Substanzen-Gesetz (New Psychoactive Substances Act).
Canada	Schedule III (CDSA)	Became a controlled substance under Schedule III of the Controlled Drugs and Substances Act on October 31, 2016.
Germany	Controlled (NpSG)	Regulated under the Neue-psychoaktive-Stoffe-Gesetz (New Psychoactive Substances Act) since November 26, 2016. Production, importation for market placement, administration to others, marketing, and trading are punishable offenses. Possession is technically illegal but not subject to criminal penalties.
Switzerland	Controlled (Verzeichnis E)	Regulated as a phenethylamine derivative under Verzeichnis E point 130 of the Betäubungsmittelverzeichnisverordnung. Exemptions exist for legitimate scientific or industrial applications.
United Kingdom	Class A	Controlled as a Class A substance under the Misuse of Drugs Act 1971 due to the phenethylamine catch-all clause. Class A drugs carry the most severe penalties, including up to 7 years imprisonment for possession and life imprisonment for supply.
United States	Unscheduled (Analogue Act applies)	Not specifically scheduled under the Controlled Substances Act. However, due to structural similarity to 2C-T-7, possession or sale intended for human consumption may be prosecuted under the Federal Analogue Act as a Schedule I equivalent. In 2004, a chemical supplier was federally indicted for distributing 2C-T-21 as a controlled substance analogue, subsequently pleading guilty in March 2005.

Harm Reduction

drugs.wiki

• Extremely rare research chemical; human data limited to PIHKAL notes and scattered community reports—assume high uncertainty in potency and effects. Keeping initial doses very low and spacing trials widely is prudent.

• For low‑milligram substances, a ±1–2 mg weighing error can double the experience. Use a calibrated milligram scale and consider volumetric dosing to dilute into a measurable liquid and reduce misdosing risk.

• Avoid redosing early: some 2C‑T‑x show variable or delayed onset; stacking doses within the first 2–3 hours can cause unexpectedly intense effects.

• Intranasal 2C‑T‑x typically causes intense burning and more adverse effects; intranasal use has been implicated in severe reactions and fatalities with 2C‑T‑7. Prefer oral administration if experimenting at all.

• Strongly avoid combining with MAOIs, tramadol, DXM, MDMA, or other potent serotonergic/stimulant drugs due to seizure, hypertensive, and serotonin‑toxicity concerns.

• Because of dose sensitivity and rarity/mislabelling risks, identify material with multiple reagents when possible and consider submitting a tiny sample to a drug checking service; some phenethylamines produce overlapping reagent colors and cannot be distinguished without lab analysis.

• Expect typical psychedelic mental health cautions: those with personal/family histories of psychotic or bipolar disorders may experience destabilization; ensure safe set/setting and a trusted sober sitter.

• Tolerance and cross‑tolerance with other serotonergic psychedelics develop rapidly; frequent use diminishes effects and may encourage risky redosing—space trials by at least a week (preferably longer).

• Emergency signs warranting medical help include severe agitation, profuse vomiting with confusion, chest pain, seizures, or loss of consciousness—these have featured in serious 2C‑T‑x adverse events.